The present invention relates to a remotely controlled locking system, including a lock mechanism for mounting to a door or a door frame, wherein the door will control access to a secured area.
There are many instances wherein it is desireable to control access to a secured area by means of a lock mechanism used on the door leading to the area. For example, modern penal institutions of the medium to high security type employ monitoring and control apparatus for cell doors. This is done to provide security for the guards, as well as for the individual inmates, as it is necessary to control door operations so as to both control the number of doors open at any one time as well as to monitor which doors are open and which doors are locked. In such systems, the doors may be controlled electrically from a remotely located control panel, accessible only to authorized personnel.
The correction officers will additionally have a master key which can mechanically unlock any door, with each inmate being issued an individual key capable of permitting the unlocking of his cell door from the exterior of the cell. Inside the cell, a push-button may be provided which can operate the cell lock enabling the prisoner to exit the cell. However, the ability of the prisoner to operate the door from either the exterior or interior is also controlled by the control panel, and as such each cell door lock can be rendered operable or inoperable by the prisoner at the election of the correction officer. To attain the desired monitoring and control of the status of each cell door and its locking mechanism, the present invention utilizes novel electrical means which are responsive to door position and to the position of selected elements of the locking mechanism for providing suitable control signals in relation thereto.
The basic structural elements of most lock mechanisms do not vary to a great extent, in that these mechanisms normally include some form of latch or latch bolt member, an external operating member such as a key-operated cylinder that is coupled for relative movement with respect to the lock mechanism, and various internal cams and/or link members for converting movement of the operating member into operation of the latch member. Additionally, such lock mechanisms often include some additional deadlock or blocking means internally which is engageable with one or more other internal members to prevent normal movement for unlocking or unlatching of the latch or latch bolt member. Such lock mechanisms may also be controlled by electrically operated means, such as a solenoid located within the lock mechanism and operated electrically from the remotely located control panel mentioned above. One example of this type of control can be found in the inventor's prior U.S. Pat. No. 4,237,711, issued Dec. 9, 1980, and entitled LOCK MECHANISMS, and in the inventor's prior U.S. Pat. No. 4,429,556, issued Feb. 7, 1984, and entitled LOCK MECHANISM.
While the specific prior art arrangements discussed above have proven satisfactory for numerous uses, there is yet room for further improvement. While useful in other types of installations, the present invention is particularly advantageous in conjunction with sliding door-type installations. In this regard, the disclosure of the present invention will be facilitated by reference to a lock of the type having a rotatably or pivotally mounted latch bolt for latching and unlatching either a door or door frame in such a sliding door type of installation. In this type of operation, it will be appreciated that when the door is open, at least a portion of the latch bolt will be accessible.
Moreover, many such installations are provided with a deadlock trigger mechanism, a portion of which is also accessible when the door is open, which normally controls operation of the deadlock mechanism discussed briefly above. As such, one trying to override the remotely controlled operation of the lock may attempt to do so by depressing the deadlock trigger into the position which it normally assumes when the door is closed. This may also be done in an effort to override the normal monitoring of door and lock position.
Similarly, when trying to override the remotely controlled electrical operation of the latch bolt, one may place considerable force on the latch itself and correspondingly upon the internal mechanism of the lock, and especially the electrical operating components. This force may become extensive enough to override or cause stalling of the electrical operating or drive components, resulting either in damage to the internal lock and drive components, or in improper indication to the correction officer of proper operation of the lock, when in fact such proper operation has been prevented.
Advantageously, the present invention utilizes novel internal components for preventing such overriding of lock operation. Moreover, the invention provides additional novel internal electrical monitoring and control components for assuring both desired operation of the lock and proper monitoring of the condition of the lock at all times.
As will be discussed more fully with reference to the detailed description and drawings which follow, there are shown several specific embodiments of the present invention. In the first embodiment, the overall lock control arrangement utilizes an electric motor for effecting operation of the lock. In a second embodiment, a solenoid is utilized in place of the electrical motor of the first embodiment. In conjunction with this second embodiment, the solenoid and internal lock structure may be constructed and assembled for either "fail-safe" or "fail-secure" operation as desired. More specifically in this regard, the solenoid and related internal lock mechanism may be of the type such that upon disruption of power, whether intentionally or due to power failure, the lock will automaticaly be placed in an open condition, thus achieving a "fail-safe" condition. On the other hand, the arrangement may be such that upon disruption of power, the lock will be placed in a latched or locked condition, thereby rendering the unit "fail-secure".